diff --git a/mq/scripts/info.py b/mq/scripts/info.py
index 41a2127..3a5fe18 100644
--- a/mq/scripts/info.py
+++ b/mq/scripts/info.py
@@ -4,6 +4,8 @@ import logging
 import redis
 import json
 
+from django.db import transaction
+
 from judge.judger_controller.settings import redis_config
 from judge.judger.result import result
 from submission.models import Submission
@@ -37,6 +39,7 @@ class MessageQueue(object):
                     problem.save()
                 except Problem.DoesNotExist:
                     logger.warning("Submission problem does not exist, submission_id: " + submission_id)
+                    continue
                 # 更新该用户的解题状态
                 try:
                     user = User.objects.get(pk=submission.user_id)
@@ -69,50 +72,46 @@ class MessageQueue(object):
                 contest_submission = ContestSubmission.objects.get(user_id=submission.user_id, contest=contest,
                                                                    problem_id=contest_problem.id)
                 # 提交次数加1
-
-                if submission.result == result["accepted"]:
-                    # 避免这道题已经 ac 了，但是又重新提交了一遍
-                    if not contest_submission.ac:
-                        # 这种情况是这个题目前处于错误状态，就使用已经存储了的罚时加上这道题的实际用时
-                        # logger.debug(contest.start_time)
-                        # logger.debug(submission.create_time)
-                        # logger.debug((submission.create_time - contest.start_time).total_seconds())
-                        # logger.debug(int((submission.create_time - contest.start_time).total_seconds() / 60))
-                        contest_submission.ac_time = int((submission.create_time - contest.start_time).total_seconds())
-                        contest_submission.total_time += contest_submission.ac_time
+                with transaction.atomic():
+                    if submission.result == result["accepted"]:
+                        # 避免这道题已经 ac 了，但是又重新提交了一遍
+                        if not contest_submission.ac:
+                            # 这种情况是这个题目前处于错误状态，就使用已经存储了的罚时加上这道题的实际用时
+                            contest_submission.ac_time = int((submission.create_time - contest.start_time).total_seconds())
+                            contest_submission.total_time += contest_submission.ac_time
+                            contest_submission.total_submission_number += 1
+                        # 标记为已经通过
+                        if contest_problem.total_accepted_number == 0:
+                            contest_submission.first_achieved = True
+                        contest_submission.ac = True
+                        # contest problem ac 计数器加1
+                        contest_problem.total_accepted_number += 1
+                    else:
+                        # 如果这个提交是错误的，就罚时20分钟
+                        contest_submission.total_time += 1200
                         contest_submission.total_submission_number += 1
-                    # 标记为已经通过
-                    if contest_problem.total_accepted_number == 0:
-                        contest_submission.first_achieved = True
-                    contest_submission.ac = True
-                    # contest problem ac 计数器加1
-                    contest_problem.total_accepted_number += 1
-                else:
-                    # 如果这个提交是错误的，就罚时20分钟
-                    contest_submission.total_time += 1200
-                    contest_submission.total_submission_number += 1
-                contest_submission.save()
-                contest_problem.save()
+                    contest_submission.save()
+                    contest_problem.save()
             except ContestSubmission.DoesNotExist:
                 # 第一次提交
-                is_ac = submission.result == result["accepted"]
-                first_achieved = False
-                ac_time = 0
-                if is_ac:
-                    ac_time = int((submission.create_time - contest.start_time).total_seconds())
-                    total_time = int((submission.create_time - contest.start_time).total_seconds())
-                    # 增加题目总的ac数计数器
-                    if contest_problem.total_accepted_number == 0:
-                        first_achieved = True
-                    contest_problem.total_accepted_number += 1
-                    contest_problem.save()
-                else:
-                    # 没过罚时20分钟
-                    total_time = 1200
-                ContestSubmission.objects.create(user_id=submission.user_id, contest=contest, problem=contest_problem,
-                                                 ac=is_ac, total_time=total_time, first_achieved=first_achieved,
-                                                 ac_time=ac_time)
-
+                with transaction.atomic():
+                    is_ac = submission.result == result["accepted"]
+                    first_achieved = False
+                    ac_time = 0
+                    if is_ac:
+                        ac_time = int((submission.create_time - contest.start_time).total_seconds())
+                        total_time = int((submission.create_time - contest.start_time).total_seconds())
+                        # 增加题目总的ac数计数器
+                        if contest_problem.total_accepted_number == 0:
+                            first_achieved = True
+                        contest_problem.total_accepted_number += 1
+                        contest_problem.save()
+                    else:
+                        # 没过罚时20分钟
+                        total_time = 1200
+                    ContestSubmission.objects.create(user_id=submission.user_id, contest=contest, problem=contest_problem,
+                                                     ac=is_ac, total_time=total_time, first_achieved=first_achieved,
+                                                     ac_time=ac_time)
 
 logger.debug("Start message queue")
 MessageQueue().listen_task()